The office of Pakistani Prime Minister Yusuf Raza Gilani said the country's president, Asif Ali Zardari, would remain in a Dubai hospital for medical checks related to a heart condition as officials sought to head off speculation that Zardari might be forced to resign.

Gilani's office said Zardari went to Dubai "following symptoms related to his preexisting heart condition." It said Zardari will "remain under observation and return to his normal functions as advised by doctors."

But the president's spokesman, Farhatullah Babar, said the medical checks were routine and denied the rumors as "untrue, imaginative and speculative."

Zardari, who took over as president in 2008, has been facing criticism from opposition parties over his handling of the country's deteriorating security situation and faltering economy.

Zardari has been under intense pressure in recent weeks following the resignation of the Pakistani ambassador to Washington over "memogate," the scandal that arose after an alleged memo to the Pentagon was disclosed in which Zardari was said to be asking for help in preventing a feared coup by the Pakistani military.

The U.S. State Department was obliged to defend U.S. aid to Pakistan following new calls from some lawmakers for a review of whether economic and military assistance to that country is serving U.S. national interests.